<!DOCTYPE html>
<html>
	<head>
		<meta http-equiv="content-type" content="text/html;charset=utf-8"  />
		<meta name="author" content="" />
		<meta name="keywords" content="" />
		<meta name="description" content="" />
		<title>game test</title>
		<style type="text/css">
			canvas {
				position: absolute;
				height: 100%;
				width: 100%;
				left: 0;
				top: 0;
			}
		</style>
	</head>
	<body>
		<canvas></canvas>
		<script type="text/javascript">
			canvas = document.querySelector('canvas');
			ctx = canvas.getContext('2d');
			canvas.width = canvas.clientWidth;
			canvas.height = canvas.clientHeight;
			ctx.setTransform(1, 0, 0, 1, canvas.width / 2, canvas.height / 2);
			ctx.fillStyle = "#aaa";
			ctx.fillRect(0, 0, 250, 100);
		</script>
	</body>
</html>